In winding machines a thread, usually assembled from a number of filaments, after stretching or as part of the stretching, can pass around a feed gallet or can be delivered by the feed gallet and pinch rollers, if desired, to a winding sleeve which may be provided along its periphery with a slit in which the oncoming thread can be captured.
In stretch winding machines especially, after the initial processing of the thread, e.g. by stretching after or during heating on one or more gallets or between gallets, for subsequent processing the threads are wound on such winding sleeves generally at a multiplicity of winding stations and usually in a cross winding operation so that successive layers of the winding are pitched in opposite directions. The individual winding units comprise, in addition to the locatable winding sleeve, a friction wheel or roller which is driven and which bears upon the outer periphery of the winding sleeve and the spool or bobbin of thread wound thereon. Other devices at each station can include a changing thread guide for assisting the feed of the thread to a new winding sleeve and a spool or bobbin holder and a spool or bobbin carriage.
The spool or bobbin after the tube has been fully wound with the thread must be exchanged for a winding sleeve adapted to receive the oncoming thread and this replacement or exchange of a full bobbin or spool for a new winding tube can be carried out automatically or manually.
With manual replacement it is necessary to apply the thread to the new winding sleeve and for that purpose a suction device, for example, a suction gun, may be provided which can be operated manually and which engages the thread, and applies it to the winding sleeve. The winding sleeve in turn engages the thread and winds it up in a multiplicity of layers, preferably with cross winding in the manner mentioned above. The winding sleeve, so that it is better able to capture the end of the thread, can have a V-shaped thread capture slit which is usually provided only over part of the periphery of the sleeve at an end portion thereof.
In German patent document DE 22 20 977 A1, a device for manipulating such threads is described which assists the manual introduction of the thread or yarn into the winding machine by feeding it to a yarn carrier which, in turn, transfers the yarn. The thread can then be separated with a cutting element so that waste can be collected by a suction device.
German patent document DE 42 33 638 A1 describes a device for winding up at least one thread in which a winding sleeve is provided with a shoulder of larger diameter. This shoulder is positioned adjacent the friction periphery of a friction wheel and is configured to pick up the starting length of a thread. A thread-guide arrangement is juxtaposed with the winding sleeve and is so oriented and constructed as to feed the thread onto the shoulder into the region of the winding sleeve. Depending upon the characteristics of the thread to be wound up on the sleeve and the design of the thread-processing zone of the machine (usually a stretch-winding machine), the following problems can arise:
(a) possibility of thread breakage between the supply gallet and the winding unit; and PA1 (b) loose turns in the thread windings on the winding sleeve, especially in the region of the thread reserve and at least partly in the initial layers of the binder or spool. PA1 (a) supplying the thread to the winding sleeve from a location such that the thread, in winding onto the sleeve, lies approximately in a plane substantially tangential to the friction roller and the winding sleeve at the contact line; PA1 (b) holding a free end of the thread with a suction element to form a span of the thread between the location and the suction element; and PA1 (c) entraining the thread along the span with a thread-guide element to the thread-capturing slit of the winding sleeve at a quadrant thereof immediately ahead of the contact line in the rotation of the winding sleeve, thereby capturing the thread on the winding sleeve and withdrawing the end from the suction element. PA1 means for supplying the thread to the winding sleeve from a location such that the thread, in winding onto the sleeve, lies approximately in a plane substantially tangential to the friction roller and the winding sleeve at the contact line; PA1 a suction element for holding a free end of the thread to form a span of the thread between the location and the suction element; and PA1 a thread-guide element for entraining the thread along the span to the thread-capturing slit of the winding sleeve at a quadrant thereof immediately ahead of the contact line in the rotation of the winding sleeve, thereby capturing the thread on the winding sleeve and withdrawing the end from the suction element.
As a consequence, an insufficiently secure thread reserve can shift or loosen. The result is a significant quality difference between yarn packages wound with excessively loose portions of the thread or yarn by comparison with normally wound yarn packages.